@vashworth This behaves like we'd want it but isn't quite done. We have to make a decision about how to wrap this up:

1. We continue down this path of looking for warning tags and I tweak mac.dart to print out my warnings but also throw them away from the build result (right now we don't throw them out but print them out).
2. We run the check for the warning twice, once from the xcodebuild script and once from the flutter cli.
3. Maybe you have another idea?

Let me know what you are thinking.

@vashworth This behaves like we'd want it but isn't quite done. We have to make a decision about how to wrap this up:

1. We continue down this path of looking for warning tags and I tweak mac.dart to print out my warnings but also throw them away from the build result (right now we don't throw them out but print them out).
2. We run the check for the warning twice, once from the xcodebuild script and once from the flutter cli.
3. Maybe you have another idea?

Let me know what you are thinking.

Okay here's what I would do

I would change this

to

    if (resultStderr.isNotEmpty) {
      final StringBuffer errorOutput = StringBuffer();
      if (result.exitCode != 0) {
        // "error:" prefix makes this show up as an Xcode compilation error.
        errorOutput.write('error: ');
      }
      errorOutput.write(resultStderr);
      echoError(errorOutput.toString());

+      // Stream stderr to the Flutter build process.
+      // When in verbose mode, `echoError` above will show the logs. So only
+      // stream if not in verbose mode to avoid duplicate logs.
+      // Also, only stream if exitCode is 0 since errors are handled separately
+      // by the tool on failure.
+      if (!verbose && exitCode == 0) {
+        streamOutput(errorOutput.toString());
+      }
    }

And change this

to

          } else {
+            if (!globals.logger.isVerbose) {
+              if (line.contains('error:')) {
+                globals.printError(line);
+              } else if (line.contains('warning:')) {
+                globals.printWarning(line);
+              }
+              continue;
+            }
            initialBuildStatus?.cancel();
            initialBuildStatus = null;
            buildSubStatus = globals.logger.startProgress(
              line,
              progressIndicatorPadding: kDefaultStatusPadding - 7,
            );
          }

I tested it out and that works for me, but let me know if you run into problems

@vashworth okay, so forwarding warning print statements to stdout only for that subprocess and avoiding the xcresult altogether. That works except it chops off the extra context that follows the warning, all the stuff in the note: block. I'll see if I can get this working the way we want.

@vashworth this is ready to review now. Let me know if you have a good idea on a more complete integration test.

friendly ping @hellohuanlin @vashworth

Let me know if you have a good idea on a more complete integration test.

I think you can do something like this for integration testing:
https://github.com/flutter/flutter/blob/master/packages/flutter_tools/test/integration.shard/xcode_dev_dependencies_test.dart

Basically, create an app, alter the AppDelegate to have the rootViewController code, then build (either flutter build or xcodebuild or both) and check the stdout/stderr for the warnings

Hello @gaaclarke, I wonder if it's required to change anything in our apps now since this merge? I previously used master and everything was fine but since this commit is included my app works in debug mode - but instantly crashes in release mode.

According to https://docs.google.com/document/d/1ZfcQOs-UKRa9jsFG84-MTFeibZTLKCvPQLxF2eskx44/edit?tab=t.0 I understood it like the info.plist has to be updated to include:

<key>UISceneDelegateClassName</key>
<string>FlutterSceneDelegate</string>

and the AppDelegate.swift file needs to be changed from:

import Flutter
import UIKit

@main
@objc class AppDelegate: FlutterAppDelegate {
  override func application(
    _ application: UIApplication,
    didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
  ) -> Bool {
    GeneratedPluginRegistrant.register(with: self)
    return super.application(application, didFinishLaunchingWithOptions: launchOptions)
  }
}

to

import Flutter
import UIKit

@main
@objc class AppDelegate: FlutterAppDelegate {

  override func application(
    _ application: UIApplication,
    didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
  ) -> Bool {
    return super.application(application, didFinishLaunchingWithOptions: launchOptions)
  }

  @objc override func registerLaunchPlugins() {
    GeneratedPluginRegistrant.register(with: self)
  }
}

This swift code change resulted in an Swift Compiler Error (Xcode): Method does not override any method from its superclass for me using the latest flutter master version from today.
I also tried only the info.plist change without the swift code change but unfortunately the app still directly crashes. Am I doing something wrong?

Any help or hint would be much appreciated, thanks a lot.

More information:
I am using these plugins:

FPPDeviceInfoPlusPlugin, FLTFirebaseAnalyticsPlugin, FLTFirebaseCorePlugin, SmartlookPlugin, GeolocatorPlugin, InAppReviewPlugin, MapboxMapsPlugin, FPPPackageInfoPlusPlugin, PathProviderPlugin, PermissionHandlerPlugin, SentryFlutterPlugin, FPPSharePlusPlugin, SqflitePlugin, SuperwallkitFlutterPlugin, URLLauncherPlugin

Flutter version:

Flutter 3.33.0-1.0.pre.380 • channel master • https://github.com/flutter/flutter.git
Framework • revision 27d9c0f (2 hours ago) • 2025-06-04 16:21:20 -0400
Engine • revision 27d9c0f (2 hours ago) • 2025-06-04 16:21:20 -0400
Tools • Dart 3.9.0 (build 3.9.0-196.0.dev) • DevTools 2.47.0

Hello @gaaclarke, I wonder if it's required to change anything in our apps now since this merge? I previously used master and everything was fine but since this commit is included my app works in debug mode - but instantly crashes in release mode.

It depends, maybe not. There is a PR open for the migration guide: flutter/website#12082

Please give that a look and hopefully that clears everything up for you.

Hello @gaaclarke, I wonder if it's required to change anything in our apps now since this merge? I previously used master and everything was fine but since this commit is included my app works in debug mode - but instantly crashes in release mode.

It depends, maybe not. There is a PR open for the migration guide: flutter/website#12082

Please give that a look and hopefully that clears everything up for you.

Spent a couple of hours trying to find the reason for the crash and turned it out it's unrelated to this topic. Created a new ticket: #170038

I will try to provide more information soon. Thanks for your quick answer anyway.